Note 5 - Investments in Joint Ventures (Details) - Condensed Income Statement of EXCOR and NTI ASEAN, and All Other Joint Ventures: (USD $)	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Condensed Income Statements, Captions [Line Items]
Net sales			$ 58,050,376	$ 54,247,135
Gross profit			27,600,668	25,852,537
Net income			5,479,724	4,728,680
Company’s share of equity in income of joint ventures	1,395,451	1,138,438	2,823,199	2,292,734
EXCOR [Member]
Condensed Income Statements, Captions [Line Items]
Net sales			18,963,579	17,451,153
Gross profit			10,072,948	9,105,579
Net income			3,763,017	3,260,575
Company’s share of equity in income of joint ventures			1,881,705	1,631,125
NTI ASEAN [Member]
Condensed Income Statements, Captions [Line Items]
Net sales			8,257,630	6,929,260
Gross profit			3,834,419	3,290,660
Net income			553,963	524,546
Company’s share of equity in income of joint ventures			276,948	262,148
All Other [Member]
Condensed Income Statements, Captions [Line Items]
Net sales			30,829,167	29,866,722
Gross profit			13,693,301	13,456,298
Net income			1,162,744	943,559
Company’s share of equity in income of joint ventures			$ 664,546	$ 399,461